1. Field of the Invention
The present invention relates to the preparation of laevulinic acid and, more especially, to the preparation of laevulinic acid from furfuryl alcohol.
2. Description of the Prior Art
Laevulinic acid or 4-oxopentanoic acid is a known intermediate for the synthesis of pharmaceuticals and other chemical compounds.
It is prepared via two different routes:
It can be prepared by heating sugars such as glucose, sucrose, molasses or starch in dilute hydrochloric acid. This preparation does not afford high yields and can hardly be used industrially.
Laevulinic acid can also be prepared by opening the ring of furfuryl alcohol in water and in the presence of an oil. Thus, U.S. Pat. No. 3,752,849 describes such a process using a water-soluble ketone as the reaction solvent. Such a process provides good yields However, the ketone used as the solvent itself intervenes in secondary aldolization and condensation reactions. By this process, a colored laevulinic acid is obtained, even after distillation, and the content of laevulinic acid does not exceed 98% because of the great difficulties in separating its impurities therefrom.